Vehicle

ABSTRACT

A vehicle includes: a vehicle body frame; a drive unit provided on the vehicle body frame and movable on a floor surface; a seat disposed above the vehicle body frame; a lift unit to raise and lower the seat between a low position and a high position; a first leg extending downward from the seat and provided with a roller at a lower end thereof; a second leg extending downward from the seat, provided with a contact member at a lower end thereof, and displaceable in an up-down direction; and a lever connected to the second leg via a transmission mechanism. When the seat is in the low position, the contact member is displaced between a use position in which the contact member contacts the floor surface and a retracted position in which the contact member is separated from the floor surface depending on a position of the lever.

TECHNICAL FIELD

The present invention relates to a vehicle including a drive unit and aseat provided on the drive unit via a lift unit.

BACKGROUND ART

JP2021-146748A discloses a vehicle including a drive unit and a seatprovided on the drive unit via a lift unit. The drive unit includes adrive wheel which is driven under an inverted pendulum control. Thevehicle disclosed in JP2021-146748A is configured to lower the positionof the seat when the user gets on and off the vehicle than when thevehicle is traveling so that the user can easily get on and off thevehicle. Also, the vehicle includes a support leg configured to begrounded when the seat is at the low position to stabilize the postureof the vehicle body when the user gets on and off the vehicle. The lowerend of the support leg is provided with a roller so that the vehicle cantravel in the state in which the support leg is grounded.

Since the support leg is grounded via the roller, the vehicle may moveinadvertently when the control of the drive unit is stopped. Therefore,in the vehicle provided with the support leg, it is desired to maintainthe vehicle in the stop state. However, there may be a case where it isdesired to move the vehicle with the roller being grounded, andtherefore, it is preferred that the stop state can be selectivelyswitched.

SUMMARY OF THE INVENTION

In view of the foregoing background, a primary object of the presentinvention is to selectively switch the stop state of the vehicle that isgrounded via a roller.

To achieve the above object, one aspect of the present inventionprovides a vehicle (1), comprising: a vehicle body frame (2); a driveunit (3) provided on the vehicle body frame and movable on a floorsurface; a seat (4) disposed above the vehicle body frame to supportbuttocks of a user; a lift unit (5) provided between the vehicle bodyframe and the seat to raise and lower the seat between a low positionand a high position; at least one first leg (24) extending downward fromthe seat and provided with a roller (23) at a lower end thereof; atleast one second leg (27) extending downward from the seat, providedwith a contact member (26) at a lower end thereof, and displaceable inan up-down direction; and at least one lever (34) connected to thesecond leg via a transmission mechanism (33), wherein when the seat isin the high position, the roller and the contact member are separatedfrom the floor surface, when the seat is in the low position, the rollercontacts the floor surface while the contact member is capable ofcontacting the floor surface, and when the seat is in the low position,the contact member is displaced between a use position in which thecontact member contacts the floor surface and a retracted position inwhich the contact member is separated from the floor surface dependingon a position of the lever.

According to this aspect, the stop state of the vehicle that is groundedvia a roller can be selectively switched. The user can displace thesecond leg between the use position and the retracted position byoperating the lever. When the seat is in the low position and the secondleg is in the use position, the contact member provided at the lower endof the second leg contacts the floor surface, whereby the vehicle ismaintained in the stop state. Since the vehicle is maintained in thestop state due to the friction force between the contact member and thefloor surface, it is unnecessary to supply electric power to the drivingdevice and thus the energy efficiency can be improved.

Preferably, the at least one lever includes a pair of levers provided onleft and right outer sides of the seat, and each lever of the pair oflevers is connected to the transmission mechanism. Also preferably, theat least one second leg includes multiple second legs connected to thetransmission mechanism, and the transmission mechanism displaces each ofthe second legs according to displacement of one lever of the pair oflevers.

According to this aspect, even in a case where the user has disabilitywith one of the left and right hands, the user can operate the leverwith the other hand.

Preferably, the transmission mechanism includes a member (44, 45) thatpulls up each of the second legs according to displacement of one leverof the pair of levers.

According to this aspect, the transmission mechanism can be simplifiedby using a machine element.

Preferably, the transmission mechanism does not transmit displacement ofone lever of the pair of levers to an other lever of the pair of levers.

According to this aspect, unnecessary movement of the levers can beomitted.

Preferably, the transmission mechanism includes an input member (41)that separably contacts the pair of levers and an output member (44, 45)that displaces each of the second legs according to displacement of theinput member, and the input member is pushed by one lever of the pair oflevers and is displaced when the one lever of the pair of levers isdisplaced from an initial position to an operation position.

According to this aspect, it is possible not to transmit displacement ofone lever of the pair of levers to the other lever.

Preferably, the vehicle comprises a lock device (38) that locks thelever in an initial position.

According to this aspect, it is possible to prevent the user frominadvertently operating the lever.

Preferably, the lever is displaced between an initial position and anoperation position, the second leg is in the use position when the leveris in the initial position and the second leg is in the retractedposition when the lever is in the operation position, and the lift unitallows displacement of the seat to the high position when the seat is inthe low position and the lever is in the initial position.

According to this aspect, the seat is prevented from moving to the highposition when the lever is in the operation position. Therefore, theseat is raised in the state in which the second leg is in the useposition and the contact member is grounded.

Preferably, the vehicle further comprises a restriction mechanism thatmaintains the lever in the initial position when the seat is in the highposition.

According to this aspect, when the seat is in the high position, thelever is maintained in the initial position and the second leg ismaintained in the use position. Therefore, when the seat moves from thehigh position to the low position, the contact member of the second legis grounded so that the vehicle is maintained in the stop state.

According to the foregoing configuration, the stop state of the vehiclethat is grounded via a roller can be selectively switched.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a vehicle according to an embodiment of thepresent invention as seen from left when the seat is in a low position;

FIG. 2 is a side view of the vehicle as seen from left when the seat isin a high position;

FIG. 3 is a perspective view of a seat frame assembly;

FIG. 4 is a sectional view of a drive unit;

FIG. 5 is a perspective view showing a lever and a transmissionmechanism;

FIG. 6 is a perspective view of the vehicle as seen from front andabove;

FIG. 7 is a plan view of the vehicle;

FIG. 8 is a sectional view of a pad of the seat; and

FIG. 9 is a side view of the vehicle as seen from left when the seat isin the low position and second legs are in a retracted position.

DETAILED DESCRIPTION OF THE INVENTION

In the following, a preferred embodiment of a vehicle according to thepresent invention will be described with reference to the appendeddrawings. In the present embodiment, the vehicle is configured as aninverted pendulum vehicle.

As shown in FIGS. 1 and 2 , the vehicle 1 includes a vehicle body frame2, at least one drive unit 3 provided on the vehicle body frame 2 andmovable on a floor surface, a seat 4 provided above the vehicle bodyframe 2 to support buttocks of a user, a lift unit 5 provided betweenthe vehicle body frame 2 and the seat 4, and a control unit 6 thatcontrols the drive unit 3 and the lift unit 5.

In this embodiment, left and right drive units 3 are provided on leftand right side portions of the vehicle body frame 2, respectively. Eachdrive unit 3 includes a drive wheel 8 that is driven under an invertedpendulum control. In the present embodiment, each drive unit 3 is afriction drive unit. As shown in FIG. 4 , the friction drive unitincludes a pair of drive disks 10 rotatably supported on the vehiclebody frame 2, multiple drive rollers 11 rotatably supported on each ofthe drive disks 10, an annular drive wheel 8 disposed between the leftand right drive disks 10 to be in contact with the drive rollers 11, anda pair of actuators 12 for individually rotating the respective drivedisks 10. The drive disks 10 are disposed mutually coaxially, and therotation axes thereof extend in the lateral direction. As shown in FIG.1 , each actuator 12 includes an electric motor 12A and a transmissionmechanism 12B that transmit the rotational force of the electric motor12A to the corresponding drive disk 10. The transmission mechanism 12Bmay be a belt transmission mechanism, for example. Preferably, theelectric motor 12A is disposed above the drive disk 10.

As shown in FIGS. 1 and 4 , the drive wheel 8 is annular in shape and isdisposed between the two drive disks 10 to be coaxial with the drivedisks 10. Also, the drive wheel 8 is in contact with the multiple driverollers 11 and is rotatable about a central axis. The drive wheel 8includes a ring core 13 and multiple driven rollers 14 rotatablysupported by the ring core 13. Each driven roller 14 is supported by thering core 13 to be rotatable about an annular center line of the ringcore 13. Each driven roller 14 receives a load from the drive disks 10and rotates relative to the ring core 13.

When the two drive disks 10 are turned in the same direction at the samerotation speed, the drive wheel 8 rotates in the same direction and atthe rotation speed as the drive disks 10. When there is a difference inthe rotation direction or the rotation speed between the two drive disks10, the driven rollers 14 of the drive wheel 8 rotate relative to thering core 13. As a result, the drive unit 3 can produce a lateralpropulsion force relative to the floor surface.

A battery is supported on a rear portion of the vehicle body frame 2.Also, a control unit 6 is mounted inside or on a rear portion of thevehicle body frame 2.

The lift unit 5 is a device for raising and lowering the seat 4 betweena low position and a high position. The seat 4 includes a seat frame 18supported by the lift unit 5 and a pad 19 supported on top of the seatframe 18. The user can be seated on the pad 19. The lift unit 5 isjoined to the vehicle body frame 2 and the seat frame 18. The lift unit5 vertically displaces the seat frame 18 relative to the vehicle bodyframe 2 by extending and contracting in the up-down direction. Forexample, the lift unit 5 may be a ball screw mechanism or arack-and-pinion mechanism driven by an electric motor, or may be alinear motor. Also, the lift unit 5 may be an air cylinder that expandsand contracts due to compressed air from a compressor.

The lift unit 5 preferably includes a base supported on the vehicle bodyframe 2, a movable body provided on the base to be vertically movableand joined to the seat frame 18, a ball screw mechanism for moving themovable body relative to the base, and an electric motor that drives theball screw mechanism, for example.

As shown in FIG. 2 , the high position of the seat 4 preferably is rightabove the low position of the seat 4. In another embodiment, the highposition of the seat 4 may be offset laterally relative to the lowposition of the seat 4.

As shown in FIG. 3 , the seat frame 18 includes a pair of left and rightside members 18A extending in the fore and aft direction, a front member18B extending laterally and joined to the front ends of the left andright side members 18A, and a rear member 18C extending laterally andjoined to the rear ends of the left and right side members 18A. The seatframe 18 is formed in a quadrilateral frame shape as seen in plan view.The seat frame 18 further includes multiple inner plates 21 extendinglaterally inward from the left and right side members 18A and joined tothe front member 18B or the rear member 18C. The multiple inner plates21 have vertically facing surfaces. Each inner plate 21 is joined to theupper end of the lift unit 5. The inner plates 21, the left and rightside members 18A, the front member 18B, and the rear member 18C supportthe pad 19 from below.

The vehicle 1 includes at least one first leg 24 extending downward fromthe seat 4 and provided with a roller 23 at a lower end thereof and atleast one second leg 27 extending downward from the seat 4 and providedwith a contact member 26 at a lower end thereof. In the presentembodiment, the vehicle 1 has four first legs 24 and four second legs27.

At each of the four corners of the seat frame 18, a leg supporting part29 that protrudes downward is provided. A front left leg supportingparts 29 is provided at the coupling part between the front end of theleft side member 18A and the left end of the front member 18B. A frontright leg supporting part 29 is provided at the coupling part betweenthe front end of the right side member 18A and the left end of the frontmember 18B. A rear left leg supporting part 29 is provided at thecoupling part between the rear end of the left side member 18A and theleft end of the rear member 18C. A rear right leg supporting part 29 isprovided at the coupling part between the rear end of the right sidemember 18A and the right end of the rear member 18C.

Each of the first legs 24 is joined to the seat frame 18 via acorresponding one of the leg supporting parts 29 and each of the secondlegs 27 is joined to the seat frame 18 via a corresponding one of theleg supporting parts 29. Namely, each leg supporting part 29 has onefirst leg 24 and one second leg 27 connected thereto. The first legs 24have the same configuration as each other, and the second legs 27 havethe same configuration as each other.

Each first leg 24 is pivotably joined to the corresponding legsupporting part 29. Each first leg 24 is pivotable between a stowedposition set near the vehicle body frame 2 and a deployed position moreseparated laterally from the vehicle body frame 2 than the stowedposition is.

The first leg 24 may include a first leg upper portion 24B and a firstleg lower portion 24C joined to each other via a joint 24A. The upperend of the first leg upper portion 24B is pivotably joined to thecorresponding leg supporting part 29. The upper end of the first leglower portion 24C is pivotably joined to the lower end of the first legupper portion 24B. The connection part between the lower end of thefirst leg upper portion 24B and the upper end of the first leg lowerportion 24C constitutes the joint 24A. Preferably, the pivot axis of thefirst leg upper portion 24B relative to the leg supporting part 29 andthe pivot axis of the first leg lower portion 24C relative to the firstleg upper portion 24B are arranged parallel to each other. In anotherembodiment, the joint 24A may be omitted and the first leg upper portion24B and the first leg lower portion 24C may be formed integrally. Also,the leg supporting part 29 and the first leg upper portion 24B may beformed integrally and the first leg lower portion 24C may be connectedto the first leg upper portion 24B via the joint 24A.

The lower end of the first leg lower portion 24C has a roller 23rotatably joined thereto. Preferably, the roller 23 is a caster having arotation shaft that rotates relative to the first leg lower portion 24Cabout a vertical axis. In another embodiment, instead of the roller 23,a ball may be supported on the lower end of the first leg lower portion24C.

The lower end of the front left first leg 24 moves forward and leftwardfrom the stowed position toward the deployed position. The lower end ofthe front right first leg 24 moves forward and rightward from the stowedposition toward the deployed position. The lower end of the rear leftfirst leg 24 moves rearward and leftward from the stowed position towardthe deployed position. The lower end of the rear right first leg 24moves rearward and rightward from the stowed position toward thedeployed position. The moving direction of each first leg 24 from thestowed position to the deployed position may be changed as appropriate.

The first leg 24 includes multiple stoppers 24D that restrict thepivoting range. Preferably, the multiple stoppers 24D are providedinside the first leg 24. The stoppers 24D are preferably provided at theconnection part between the leg supporting part 29 and the upper end ofthe first leg upper portion 24B and at the connection part between thelower end of the first leg upper portion 24B and the upper end of thefirst leg lower portion 24C.

The first leg 24 includes urging members (not shown in the drawings) forurging the first leg 24 from the deployed position toward the stowedposition. Specifically, the urging members are preferably provided atthe connection part between the leg supporting part 29 and the upper endof the first leg upper portion 24B and at the connection part betweenthe lower end of the first leg upper portion 24B and the upper end ofthe first leg lower portion 24C. Each urging member may be a torsionspring, a tension coil spring, a compression coil spring, or the like.Each first leg 24 is displaced from the stowed position to the deployedposition when the roller 23 is pushed by the floor surface. Also,dampers (not shown in the drawings) may be provided at the connectionpart between the leg supporting part 29 and the upper end of the firstleg upper portion 24B and at the connection part between the lower endof the first leg upper portion 24B and the upper end of the first leglower portion 24C. Each damper preferably is a rotation damper, a pistondamper or the like.

The second leg 27 is capable of extending and contracting in the up-downdirection and is urged in the extending direction. The second leg 27includes a second leg upper portion 27A extending downward from thecorresponding leg supporting part 29 and a second leg lower portion 27Bsupported on the second leg upper portion 27A to be movable in theup-down direction. Preferably, the second leg upper portion 27A isformed of a linearly extending pipe and the second leg lower portion 27Bis formed of a pipe slidably receiving the second leg upper portion 27A,for example.

The lower end of the second leg lower portion 27B is provided with acontact member 26. The contact member 26 preferably has flexibilityhigher than that of the second leg lower portion 27B. Also, the contactmember 26 preferably has a friction coefficient higher than that of thesecond leg lower portion 27B. The contact member 26 is preferably madeof rubber or elastomer, for example. With the contact member 26 of eachsecond leg 27 contacting the ground, the vehicle 1 grounded via therollers 23 can be maintained in the stop state. Due to the frictionforce between the contact member 26 provided at the lower end of eachsecond leg 27 and the floor surface, the vehicle 1 is maintained in thestop state. Since the vehicle is maintained in the stop state due to thefriction force between the contact member 26 and the floor surface, itis unnecessary to supply electric power to the drive units 3 and thusthe energy efficiency can be improved. Also, as a result of making thevehicle 1 stopped, it becomes easy to determine the position of thecenter of gravity of the vehicle 1 when the seat 4 is moved to the highposition and the inverted pendulum control is started.

Between the second leg upper portion 27A and the second leg lowerportion 27B, an urging member is interposed to urge the second leg lowerportion 27B downward relative to the second leg upper portion 27A. Theurging member preferably is a compression coil spring. Preferably, theurging member is disposed inside the second leg lower portion 27B and isin contact with the lower end of the second leg upper portion 27A. Thesecond leg 27 is urged in the extending direction by the urging member.

Each second leg 27 includes a damper 27C for attenuating the extendingand contracting movement. The damper 27C may be a piston damper. Thedamper 27C extends vertically and includes an upper end joined to thesecond leg upper portion 27A and a lower end joined to the second leglower portion 27B. Instead of being joined to the second leg upperportion 27A, the upper end of the damper 27C may be joined to the legsupporting part 29 to which the second leg upper portion 27A is joined.

Each second leg 27 is provided closer to the vehicle body frame 2 thanthe correspond first leg 24 is. The front left second leg 27 is disposedmore rightward and rearward than the front left first leg 24, the frontright second leg 27 is disposed more leftward and rearward than thefront right first leg 24, the rear left second leg 27 is disposed morerightward and forward than the rear left first leg 24, and the rearright second leg 27 is disposed more leftward and forward than the rearright first leg 24.

The lower portions of adjacent ones of the second legs 27 are connectedto each other by a coupling member 31. In the present embodiment, thefront left second leg lower portion 27B and the front right second leglower portion 27B are connected by a laterally extending coupling member31, and the rear left second leg lower portion 27B and the rear rightsecond leg lower portion 27B are connected by another laterallyextending coupling member 31.

As shown in FIG. 2 , when the seat 4 is in the high position, eachroller 23 and each contact member 26 are separated from the floorsurface. When the seat 4 is in the high position, the lower end of eachcontact member 26 is disposed lower than the lower end of each roller23. As shown in FIG. 1 , when the seat 4 is in the low position, eachroller 23 and each contact member 26 contact the floor surface. When theseat 4 moves from the high position to the low position, each contactmember 26 comes into contact with the floor surface earlier than eachroller 23 does. Therefore, when the seat 4 moves to the low position,the vehicle can be brought into the stop state early.

Since each second leg 27 is configured to be capable of extending andcontracting in the up-down direction, each contact member 26 canreliably contact the floor surface. Also, since each second leg 27 isprovided with the damper 27C, an impact when the seat 4 reaches the lowposition can be reduced. Since adjacent ones of the second leg lowerportion 27B are coupled by the coupling member 31, the stiffness of eachsecond leg 27 increases. Therefore, each second leg 27 can restrict themovement of the vehicle 1 reliably.

Each first leg 24 is moved from the stowed position to the deployedposition when pushed by the floor surface. Thereby, the distance betweenthe ground-contact points of the first legs 24 is increased so that theposture of the vehicle 1 in the low position is stabilized.

As shown in FIG. 5 , the second leg lower portion 27B of each second leg27 is connected to at least one lever 34 via a transmission mechanism33. In the present embodiment, a pair of left and right levers 34 isprovided. The left and right levers 34 and their support structures arebilaterally symmetrical, and therefore, in the following, descriptionwill be made of the left lever 34 and its support structure.

A rear lever support 36 is provided on the rear portion of the sidemember 18A. The rear lever support 36 extends upward from thecorresponding side member 18A. The base end portion of the lever 34 ispivotably joined to the rear lever support 36. The pivot axis of thelever 34 extends in the lateral direction. The lever 34 pivots betweenan initial position in which the lever 34 extends forward andhorizontally from the base end portion and an operation position inwhich the lever 34 is located when caused to pivot upward and rearwardfrom the initial position.

A front lever support 37 is provided on the front portion of the sidemember 18A. The front lever support 37 extends rearward from thecorresponding side member 18A. The upper end of the front lever support37 is formed with a lever receiving part 37A for receiving the tip endportion of the lever 34 in the initial position. The front lever support37 supports the tip of the lever 34 in the initial position from below.

The front lever support 37 includes a lock device 38 for locking thelaterally corresponding lever 34 in the initial position. The lockdevice 38 includes a displacement member 38C displaceably supported onthe front lever support 37 and having a locking claw 38A and a tab 38B,and an urging member (not shown in the drawings) that urges thedisplacement member 38C. The displacement member 38C is preferablyprovided on the front lever support 37 to be pivotable or to beslidingly movable. The displacement member 38C is displaceable between aprotruding position in which the locking claw 38A protrudes into thelever receiving part 37A and a release position in which the lockingclaw 38A retreats into the front lever support 37. The tab 38B protrudesout from the front lever support 37. Preferably, the tab 38B protrudesdownward from the front lever support 37. The urging member urges thedisplacement member 38C toward the protruding position. The tip of thelever 34 is formed with a locking hole 38D for receiving the lockingclaw 38A. With the locking claw 38A protruding into the locking hole38D, the lever 34 is maintained in the initial position. When thedisplacement member 38C moves to the release position, the lever 34becomes able to pivot from the initial position to the operationposition. By operating the tab 38B, the user can cause the displacementmember 38C to move the release position.

Each of the multiple second legs 27 is connected to the transmissionmechanism 33. The transmission mechanism 33 displaces each of the secondlegs 27 according to displacement of one of the two levers 34. Thetransmission mechanism 33 pulls up each of the second legs 27 accordingto displacement of one of the two levers 34. Also, the transmissionmechanism 33 does not transmit the displacement of one of the two levers34 to the other of the two levers 34.

The transmission mechanism 33 includes a pair of left and right inputmembers 41, a drive shaft 42, a pair of left and right first links 43, apair of left and right second links 44, a pair of left and right controlcables 45, and a pair of left and right lock arms 46. In thetransmission mechanism 33, the left and right elements have identicalconfiguration, and therefore, description may be made of one of the leftand right elements where appropriate.

The input member 41 is pivotably supported by the rear lever support 36.The pivot axis of the input member 41 is arranged to be coaxial with thepivot axis of the lever 34. The input member 41 pivots between aninitial position and an operation position. The lever 34 is providedwith a first pressing part 34A. The first pressing part 34A may be a pinjoined to the lever 34. When the lever 34 pivots from the initialposition to the operation position, the first pressing part 34A pressesthe input member 41, and the input member 41 pivots from the initialposition to the operation position. On the other hand, when the lever 34is in the initial position, the input member 41 can be separated fromthe first pressing part 34A to pivot to the operation position. Namely,the input member 41 separably contacts the lever 34.

The drive shaft 42 extends laterally. The left end of the drive shaft 42is pivotably supported by the left rear lever support 36 and the rightend of the drive shaft 42 is pivotably supported by the right rear leversupport 36. The drive shaft 42 has a pair of left and right first arms42A and a pair of left and right second arms 42B. The left first arm 42Aand the left second arm 42B are provided at the left end of the driveshaft 42, and the right first arm 42A and the right second arm 42B areprovided at the right end of the drive shaft 42. The first arms 42A andthe second arms 42B protrude in the radial direction of the drive shaft42. The left first arm 42A is connected to the left input member 41 by afirst link 43, and the left second arm 42B is connected to the rear leftsecond leg lower portion 27B by a second link 44. The right first arm42A is connected to the right input member 41 by a first link 43, andthe right second arm 42B is connected to the rear right second leg lowerportion 27B by a second link 44.

The control cable 45 includes a tubular outer casing 45A and an innercable 45B slidably supported inside the outer casing 45A. One end of theouter casing 45A of the left control cable 45 is joined to the left rearlever support 36, and the other end is joined to the front left secondleg upper portion 27A or the front left leg supporting part 29. One endof the inner cable 45B of the left control cable 45 is connected to theleft input member 41, and the other end is connected to the front leftsecond leg lower portion 27B. Similarly, one end of the outer casing 45Aof the right control cable 45 is joined to the right rear lever support36, and the other end is joined to the front right second leg upperportion 27A or the front right leg supporting part 29. One end of theinner cable 45B of the right control cable 45 is connected to the rightinput member 41, and the other end is connected to the front rightsecond leg lower portion 27B.

Each second leg 27 is urged in the extending direction by an urgingmember. The urging force on the second leg 27 on the rear side istransmitted to the input member 41 via the second link 44, the driveshaft 42, and the first link 43, so that the input member 41 is urgedtoward the initial position. Also, the urging force on the second leg 27on the front side is transmitted to the input member 41 via the controlcable 45, so that the input member 41 is urged toward the initialposition.

The lock arm 46 is pivotably supported by the rear lever support 36. Thelock arm 46 is disposed around the input member 41 and is urged towardthe input member 41 by an urging member. When the input member 41 is inthe operation position, the lock arm 46 locks the input member 41 andmaintains the input member 41 in the operation position. Preferably, thelock arm 46 and the input member 41 include engagement parts that engageeach other when the input member 41 is in the operation position. Thetip end portion of the lever 34 is provided with a release button 34C.The release button 34C is connected to the lock arm 46 via atransmission member 34D. When the release button 34C is pushed in, thetransmission member 34D is moved toward the lock arm 46 in accordancewith the movement of the release button 34C, and the transmission member34D pushes the lock arm 46 in a direction away from the input member 41.As a result, the locking of the input member 41 by the lock arm 46 isreleased, and the input member 41 can return to the initial positionunder the urging force of the urging member. The release button 34C andthe transmission member 34D are preferably connected via a cam, forexample. The transmission member 34D is urged in a direction away fromthe lock arm 46 by an urging member.

When the user operates the left lever 34 to pivot from the initialposition to the operation position, the first pressing part 34A of theleft lever 34 pushes the left input member 41, and the left input member41 pivots from the initial position to the operation position. When theleft input member 41 pivots, the left first link 43 causes the driveshaft 42 to pivot. The pivoting of the drive shaft 42 causes the leftand right second links 44 to move upward, and the left and right secondlinks 44 pull up the rear left and rear right second leg lower portions27B upward against the urging force. Namely, as shown in FIG. 9 , therear left and rear right second legs 27 contract.

Also, when the drive shaft 42 rotates, the right first link 43 causesthe right input member 41 to pivot from the initial position to theoperation position. At this time, the right input member 41 pivotsindependently from the right lever 34, and therefore, the right lever 34is maintained in the initial position. Namely, displacement of one ofthe two levers 34 is not transmitted to the other of the two levers 34.

When the left and right input members 41 pivot toward the operationposition, the corresponding control cables 45 cause the front left andfront right second leg lower portions 27B to move upward against theurging forces of the corresponding urging members. Namely, the frontleft and front right second legs 27 contract.

If the user operates the lever 34 to pivot to the operation positionwhen the seat 4 is in the low position, the all second legs 27 contract,and the contact members 26 move from the use position in which thecontact members 26 are in contact with the floor surface to theretracted position in which the contact members 26 are separated fromthe floor surface. In this way, when the seat 4 is in the low position,the contact members 26 are displaced between the use position and theretracted position according to the position of the lever 34. The leftand right first links 43, the drive shaft 42, the left and right secondlinks 44, and the left and right control cables 45 function as an outputmember for displacing each of the second legs 27 according todisplacement of the input member 41.

As shown in FIG. 3 , the vehicle 1 includes at least one support member51 extending downward from the seat 4. The support member 51 has afootrest 51A at the lower portion thereof to support the soles of theuser. In the present embodiment, the vehicle 1 includes a pair of leftand right support members 51. Each support member 51 is provided to bevertically displaceable relative to the seat 4.

In correspondence with the pair of left and right support members 51,the seat 4 includes a pair of left and right tubular receiving parts 53that extend vertically. The left receiving part 53 is provided on thefront left leg supporting part 29, and the right receiving part 53 isprovided on the front right leg supporting part 29. Each support member51 includes a shaft part 51B slidably supported by the receiving part 53and a stopper 51C provided on the upper portion of the shaft part 51B.The footrest 51A is joined to the lower portion of the shaft part 51B.The stopper 51C defines the lower limit position of the shaft part 51Brelative to the receiving part 53 by contacting the upper end of thereceiving part 53. The shaft part 51B is preferably formed of a pipematerial, for example.

When the seat 4 is in the low position, the lower ends of the left andright footrests 51A contact the upper surface of the coupling member 31,and each stopper 51C is disposed in a position separated upward from thereceiving part 53. In this state, the lower end of the shaft part 51B isseparated from the floor surface. When the seat 4 moves from the lowposition toward the high position, the front left and front right secondlegs 27 extend, and the receiving parts 53 ascend relative to thesupport members 51. Therefore, as the seat 4 ascends, the distancebetween the seat 4 and the footrests 51A increases. Thereafter, when theseat 4 ascends further, the receiving parts 53 come into contact withthe stoppers 51C.

The lower end of each shaft part 51B may be provided with a roller 51D.In this case, it is preferred if the lower end of the shaft part 51Bcontacts the floor surface via the roller 51D. Thereby, the vehicle 1can travel in the state in which the support members 51 are in contactwith the ground.

Preferably, the left and right shaft parts 51B are joined to each otherby a coupling member 54 that extends laterally. The left and right shaftparts 51B are disposed between the front left second leg 27 and thefront right second leg 27. The left and right footrests 51A extendforward and laterally inward from the corresponding shaft parts 51B.

When the seat 4 is in the low position, the lower end of each shaft part51B contacts the floor surface via the roller 51D, and each stopper 51Cis disposed in a position separated upward from the receiving part 53.When the seat 4 moves from the low position toward the high position,each receiving part 53 ascends relative to the support member 51. Duringthis, each support member 51 is maintained in contact with the ground.Therefore, as the seat 4 ascends, the distance between the seat 4 andthe footrest 51A increases. Thereafter, when the seat 4 ascends further,the receiving part 53 comes into contact with the stopper 51C. When theseat 4 ascends further with the receiving part 53 contacting the stopper51C, the support member 51 ascends integrally with the seat 4, and thelower end of the shaft part 51B leaves the floor surface.

When the seat 4 is in the high position, the stopper 51C is in contactwith the receiving part 53. When the seat 4 moves from the high positiontoward the low position, the support member 51 descends together withthe receiving part 53. Thereafter, when the seat 4 reaches a certainheight, the lower end of the shaft part 51B of the support member 51contacts the floor surface via the roller 51D, and the descent of thesupport member 51 ends. Subsequently, the receiving part 53 is separatedfrom the stopper 51C and moves downward relative to the support member51. Therefore, as the seat 4 descends, the distance between the seat 4and the footrest 51A decreases. In this way, the support member 51 isdisplaced such that the distance L2 between the seat 4 and the footrest51A when the seat 4 is in the high position (see FIG. 2 ) is greaterthan the distance L1 between the seat 4 and the footrest 51A when theseat 4 is in the low position (see FIG. 1 ).

The shaft part 51B moves in the up-down direction relative to thereceiving part 53. Therefore, the angle and the front-rear position ofthe footrest 51A relative to the seat 4 when the seat 4 is in the lowposition are the same as the angle and the front-rear position of thefootrest 51A relative to the seat 4 when the seat 4 is in the highposition. Thus, since the angle and the front-rear position of thefootrest 51A relative to the seat 4 do not change even when the seat 4moves from the low position to the high position, the posture of theuser is kept stable.

When the seat 4 is in the high position, the lower end of the contactmember 26 of the second leg 27 is disposed lower than the lower end ofthe roller 23 of the first leg 24 and the lower end of the roller 51D ofthe shaft part 51B is disposed higher than the lower end of the contactmember 26. As a result, the contact member 26 comes into contact withthe ground earlier than the support member 51. Thereby, the supportmember 51 can be grounded with good stability with the movement of thevehicle 1 being restricted by the contact member 26.

The upper surface of the pad 19 contacts the buttocks and the thighs ofthe user. The front portion of the upper surface of the pad 19 contactsthe thighs of the user, while the rear portion of the upper surface ofthe pad 19 contacts the buttocks of the user. As shown in FIGS. 6 to 8 ,the upper surface of the front portion of the pad 19 includes aninclined surface 19A that is inclined downward in the forward direction.Specifically, the inclined surface 19A extends from the front end of thepad 19 to the central portion of the pad 19 in the front-rear direction.The inclined surface 19A may extend rearward beyond the central portionof the pad 19 in the front-rear direction. Thereby, the thighs of theuser seated on the seat 4 are inclined downward toward the knees.

The upper surface of the rear portion of the pad 19 is provided with arecess 19B that is recessed downward. The recess 19B accommodate theischia of the user. The recess 19B supports the ischia of the user andprevents the ischia of the user from moving forward and rearwardrelative to the pad 19.

Left and right side portions 19C of the front portion of the pad 19 areinclined laterally inward in the forward direction as seen from above.The pad 19 includes a pair of left and right bank parts 19D on the leftand right side portions thereof such that the bank parts 19D protrudeupward. The pair of left and right bank parts 19D suppresses lateralmovement of the buttocks of the user. The rear portion the pad 19 may beprovided with a backrest 19E that protrudes upward.

The seat 4 is provided with a knee belt 55 for restraining the knees ofthe user on the front portion of the pad 19. The knee belt 55 includes aleft knee belt 55 joined to the left side member 18A or the left frontlever support 37 and a right knee belt 55 joined to the right sidemember 18A or the right front lever support 37. The left and right kneebelts 55 are detachably joined to each other by means of couplingmembers 56 such as a buckle and a tongue.

As shown in FIGS. 6 and 7 , the vehicle 1 includes an operation device60 provided on at least one of the left side portion and the right sideportion of the seat 4. In the present embodiment, two operation devices60 are provided on the left side portion and the right side portion ofthe seat 4, respectively. Thereby, even in a case where the user hasdisability with one of the left and right hands, the user can operatethe vehicle with the other hand. Preferably, the left and rightoperation devices 60 have an identical configuration.

The operation device 60 includes an operation panel 60B having anoperation surface 60A that faces upward, and multiple operation members61 provided on the operation surface 60A. The lever 34 constitutes apart of the operation device 60 and extends upward and forward from therear portion of the operation panel 60B.

The operation panel 60B is disposed to cover the lower portion of thefront lever support 37 and the rear lever support 36. The operationpanel 60B is preferably supported on at least one of the front leversupport 37, the rear lever support 36, and the seat frame 18. Theoperation panel 60B extends in the fore and aft direction along the sideportion 19C of the pad 19. The lever 34 extends in the fore and aftdirection above the operation panel 60B. Since the side portion 19C ofthe front portion of the pad 19 extends to be inclined laterally inward,the distance between the front end portion of the lever 34 and the pad19 in the lateral direction is greater than the distance between therear end portion of the lever 34 and the pad 19 in the lateraldirection. The upper portion of the front lever support 37 protrudesupward from the operation panel 60B.

As shown in FIG. 7 , the multiple operation members 61 preferablyinclude a power switch 61A, a lifting switch 61B, a moving directionswitch 61C, and a travel mode selector switch 61D. The power switch 61A,the lifting switch 61B, the moving direction switch 61C, and the travelmode selector switch 61D are preferably provided on each of the left andright operation devices 60. The multiple switches are connected to thecontrol unit 6.

As seen from above, at least one the multiple operation members 61 isdisposed in a position overlapping with the lever 34. Preferably, theoperation panel 60B is provided with a recess 60C that is recesseddownward from the operation surface 60A below the lever 34. Alsopreferably, at least one of the multiple operation members 61 isdisposed in a bottom portion of the recess 60C. In the presentembodiment, the power switch 61A and the lifting switch 61B are disposedin positions overlapping with the lever 34, and the power switch 61A andthe lifting switch 61B are disposed in the bottom portion of the recess60C. Since the lever 34 is disposed above at least one of the operationmembers 61, the user is prevented from inadvertently touching theoperation members 61. Therefore, it is possible to prevent erroneousoperation of the operation members 61 by the user. The at least oneoperation member 61 disposed below the lever 34 preferably includesthose that can significantly influence the behavior of the vehicle 1,such as the lifting switch 61B and the power switch 61A. Also, sincesome of the operation members 61 are disposed in the recess 60C, it ispossible to prevent erroneous operation of these operation members 61 bythe user even more reliably. The user can operate the power switch 61Aand the lifting switch 61B through a gap between the front portion ofthe lever 34 and the pad 19.

The operation surface 60A is disposed lower than the upper edge of thebank part 19D. Therefore, the user's inadvertently touching of theoperation members 61 disposed on the operation surface 60A can beprevented even more effectively. In the initial position, the lever 34is disposed at the same height as the upper edge of the bank part 19D.

The moving direction switch 61C is a switch for operating the driveunits 3. The moving direction switch 61C preferably is a joystick. Themoving direction switch 61C is disposed between the front end portion ofthe lever 34 and the pad 19 as seen from above. Therefore, the user canoperate the moving direction switch 61C, which is a joystick, withoutbeing obstructed by the lever 34.

At least one of the multiple operation members 61 may be lighted. Theuser can recognize the position and the activation state of theoperation member 61 based on lighting of the operation member 61. Atleast one of the multiple operation members 61 preferably displays thestate of the vehicle 1 by being lighted. For example, the power switch61A is preferably lighted when the power supply of the vehicle 1 is on,namely, when in the activated state. Also, the lifting switch 61B ispreferably lighted when the lift unit 5 is driving. The travel modeselector switch 61D may change the color of the emitted light accordingto the selected travel mode.

The control unit 6 turns the power supply of the vehicle 1 on/offaccording to an operation of the power switch 61A by the user. Thecontrol unit 6 drives the lift unit 5 to raise/lower the seat 4according to an operation of the lifting switch 61B by the user. Thecontrol unit 6 switches the travel mode of the vehicle 1 between aturning mode and a parallel movement mode according to an operation ofthe travel mode selector switch 61D by the user.

When the seat 4 is in the low position and one of the levers 34 is inthe operation position, the control unit 6 controls the drive units 3according to an operation of the moving direction switch 61C by the userto make the vehicle 1 travel. Preferably, the position of the seat 4 andthe position of the lever 34 are detected by sensors connected to thecontrol unit 6. When the turning mode is selected, the control unit 6preferably causes the vehicle 1 to turn in a lateral directioncorresponding a lateral direction operation of the moving directionswitch 61C. Also, when the parallel movement mode is selected, thecontrol unit 6 preferably causes the vehicle 1 to make a parallelmovement in a lateral direction corresponding to a lateral directionoperation of the moving direction switch 61C.

Since the lever 34 in the initial position is supported by the frontlever support 37 from below, the user can use the lever 34 as a handrailwhen getting on and off the vehicle 1. Also, since the lever 34 in theinitial position is disposed at the same height as the upper edges ofthe bank parts 19D, the user can easily use the lever 34 as a handrailwhen getting on and off the vehicle 1.

As shown in FIG. 6 , the left and right knee belts 55 extend from theleft and right side members 18A or the left and right front leversupports 37 to pass through the front end portions of the left and rightoperation panels 60B to outside, respectively. The knee belts 55cooperate with the front end portion of the pad 19 to restrain the kneesof the user, thereby to make the user stably seated on the seat 4. Also,the seat frame 18 is provided with a waist belt 71 for restraining thewaist of the user to the seat 4. The waist belt 71 includes a left waistbelt 71 extending from the rear portion of the left side member 18A topass through the rear portion of the left operation panel 60B and aright waist belt 71 extending from the rear portion of the right sidemember 18A to pass through the rear portion of the right operation panel60B. The tips of the left and right waist belts 71 are provided withcoupling members 72 that are detachably joined to each other.

An outer shell 75 may be attached to the lower portion of the vehicle 1.Preferably, each second leg 27, the shaft part 51B of each supportmember 51, and the first leg upper portion 24B of each first leg 24 aredisposed inside the outer shell 75. The lower end of the first leg lowerportion 24C of each first leg 24 preferably protrudes to the outside ofthe outer shell 75.

An operation of the vehicle 1 configured as described above will bedescribed in the following. As shown in FIG. 1 , when the seat 4 is inthe low position and the lever 34 is in the initial position, the drivewheels 8 of the left and right drive units 3, the roller 23 of eachfirst leg 24, the contact member 26 of each second leg 27, and the lowerend of each support member 51 are grounded. In this state, since eachcontact member 26 is grounded, movement of the vehicle 1 in thehorizontal direction is restricted. This state is referred to as a stopstate of the vehicle 1. When the vehicle 1 is in the stop state, theuser can get on and off the vehicle 1. At this time, the user can usethe left and right levers 34 as handrails.

When the user moves one of the levers 34 from the initial position tothe operation position in the stop state of the vehicle 1, each secondleg 27 contracts upward so that each contact member 26 is separated fromthe floor surface as shown in FIG. 9 . This state is referred to as alow position travelable state. In the low position travelable state, theuser can make the vehicle 1 travel by operating the moving directionswitch 61C. When the user moves the lever 34 to the operation position,the lock arm 46 locks the input member 41 to maintain the input member41 in the operation position. Therefore, the user can return the lever34 to the initial position to be locked by the lock device 38. When theuser presses the release button 34C, each second leg 27 extends so thateach contact member 26 is grounded, and the vehicle 1 is brought intothe stop state.

When the user operates the lifting switch 61B in the stop state of thevehicle 1, the control unit 6 drives the lift unit 5 so that the seat 4moves from the low position to the high position as shown in FIG. 2 . Asa result of the raising of the seat 4, the roller 23 of each first leg24 and the contact member 26 of each second leg 27 are separated fromthe floor surface. At this time, each support member 51 is maintained incontact with the coupling member 31 until the stopper 51C contacts thereceiving part 53, and therefore, the distance between the footrest 51Aand the seat 4 increases.

After each support member 51 is separated from the floor surface, onlythe drive wheels 8 of the left and right drive units 3 are in contactwith the ground. At this time, the posture of the vehicle 1 ismaintained by the inverted pendulum control. In this state, the controlunit 6 detects displacement of the center of gravity of the vehicle 1due to movement of the user's weight and controls the drive units 3 tomake the vehicle 1 travel accordingly.

Due to movement of the seat 4 from the low position to the highposition, the knees of the user seated on the seat extend (the kneeangle becomes large) and an amount of forward protrusion of the knees isdecreased. Therefore, the footprint of the vehicle 1 including the user,namely, the occupied area of the vehicle 1 including the user as seenfrom above, becomes smaller. As a result, the vehicle can easily move innarrow locations. In addition, when the seat 4 moves from the lowposition to the high position, the height of the eyes of the user seatedon the seat 4 becomes higher. Also, since the legs of the user seated onthe seat 4 extend vertically, the user's back is straightened and theposture of the user becomes easier to stabilize. Therefore, even whenthe seat 4 is raised to the high position, the user can have a sense ofease. Thus, it is possible to provide a vehicle which can raise theheight of the user's eyes while giving a sense of ease to the user.Since the support member 51 on which the footrest 51A is provided isdisplaced relative to the seat 4 due to gravity, no power is necessaryfor the support member 51. Thus, the energy efficiency of the vehicle 1can be improved.

Concrete embodiments of the present invention have been described in theforegoing, but the present invention is not limited to the aboveembodiments and may be modified or altered in various ways. For example,the control unit 6 may prohibit the operation of the lift unit 5 whenthe input member 41 is not locked to the lock arm 46. Also, it ispreferred if the control unit 6 permits raising of the seat 4 by thelift unit 5 when the seat 4 is in the low position and the lever 34 isin the initial position. According to this configuration, it is possibleto prevent the seat 4 from being positioned in the high position in thestate in which the second legs 27 are in the retracted position.

The vehicle 1 may include a restriction mechanism that maintains thelever 34 in the initial position when the seat 4 is in the highposition. Preferably, the restriction mechanism is constituted of anactuator that restricts the movement of the lock device 38 and thecontrol unit 6 that controls the actuator, for example. Preferably, thecontrol unit 6 detects the position of the seat 4, drives the actuatorwhen the seat 4 is in the high position to maintain the displacementmember 38C of the lock device 38 in the lock position. On the otherhand, the control unit 6 preferably separates the actuator from thedisplacement member 38C when the seat 4 is in the low position to allowrotation of the displacement member 38C.

1. A vehicle, comprising: a vehicle body frame; a drive unit provided onthe vehicle body frame and movable on a floor surface; a seat disposedabove the vehicle body frame to support buttocks of a user; a lift unitprovided between the vehicle body frame and the seat to raise and lowerthe seat between a low position and a high position; at least one firstleg extending downward from the seat and provided with a roller at alower end thereof; at least one second leg extending downward from theseat, provided with a contact member at a lower end thereof, anddisplaceable in an up-down direction; and at least one lever connectedto the second leg via a transmission mechanism, wherein when the seat isin the high position, the roller and the contact member are separatedfrom the floor surface, when the seat is in the low position, the rollercontacts the floor surface while the contact member is capable ofcontacting the floor surface, and when the seat is in the low position,the contact member is displaced between a use position in which thecontact member contacts the floor surface and a retracted position inwhich the contact member is separated from the floor surface dependingon a position of the lever.
 2. The vehicle according to claim 1, whereinthe at least one lever includes a pair of levers provided on left andright outer sides of the seat, and each lever of the pair of levers isconnected to the transmission mechanism.
 3. The vehicle according toclaim 2, wherein the at least one second leg includes multiple secondlegs connected to the transmission mechanism, and the transmissionmechanism displaces each of the second legs according to displacement ofone lever of the pair of levers.
 4. The vehicle according to claim 3,wherein the transmission mechanism includes a member that pulls up eachof the second legs according to displacement of one lever of the pair oflevers.
 5. The vehicle according to claim 2, wherein the transmissionmechanism does not transmit displacement of one lever of the pair oflevers to an other lever of the pair of levers.
 6. The vehicle accordingto claim 5, wherein the transmission mechanism includes an input memberthat separably contacts the pair of levers and an output member thatdisplaces each of the second legs according to displacement of the inputmember, and the input member is pushed by one lever of the pair oflevers and is displaced when the one lever of the pair of levers isdisplaced from an initial position to an operation position.
 7. Thevehicle according to claim 1, further comprising a lock device thatlocks the lever in an initial position.
 8. The vehicle according toclaim 1, wherein the lever is displaced between an initial position andan operation position, the second leg is in the use position when thelever is in the initial position and the second leg is in the retractedposition when the lever is in the operation position, and the lift unitallows displacement of the seat to the high position when the seat is inthe low position and the lever is in the initial position.
 9. Thevehicle according to claim 8, further comprising a restriction mechanismthat maintains the lever in the initial position when the seat is in thehigh position.